Project Summary/Abstract: Young people are disproportionately affected by the current opioid crisis including worse retention and outcomes compared to older adults. Further, young adults typically do not have access to medications for opioid use disorder (OUD), and for those that do, struggles with adherence are a major barrier. Standard approaches to treatment typically do not incorporate developmentally informed strategies for engagement, retention, and medication adherence for this special population. The Youth Opioid Recovery Support (YORS) model is an innovative wrap-around approach that attempts to address barriers to treatment engagement in this vulnerable young adult population, especially difficulties with medication adherence. Its components include: (1) Home delivery of extended release naltrexone (XR- NTX) for OUD; (2) Engagement of families in collaborative treatment planning and monitoring focusing on medication adherence; (3) Assertive outreach from the treatment team including actively tracking and communicating with youth and families by text messaging and social media to promote engagement and adherence; and (4) Contingency management to provide incentives for medication adherence. YORS is currently showing very promising results in a small pilot RCT by the investigative team. We propose to refine and then conduct a more definitive test of the YORS intervention for youth with OUD using the R61/R33 mechanism. In the R61 phase we will conduct stakeholder focus groups to get input and feedback on potential refinements, while also conducting 3 cycles of pilot testing of these potential refinements. Based on the R61 preparation and final synthesis of the intervention refinements, in the R33 phase we will conduct an RCT to test the efficacy of YORS, by randomizing N=120 young adults ages 18-26 seeking treatment for OUD with XR-NTX at Mountain Manor Treatment Center (MMTC), to either the refined YORS intervention or treatment as usual (TAU) for a 6-month course of treatment with XR-NTX. The primary outcome will be number of XR-NTX doses received. Secondary outcomes will include opioid relapse, days of opioid use, time to first opioid relapse, HIV risk behaviors, criminal behaviors, psychiatric symptoms, and family member distress and self-efficacy. It is hypothesized that participants in the YORS condition will receive significantly more XR-NTX doses and will demonstrate less severe opioid use and associated behaviors compared to those in the TAU group. The assertive YORS intervention has the potential to improve the real-world effectiveness and public health impact of medication for OUD in this very high-risk, vulnerable population. If the refined YORS intervention is found to be efficacious, it would set the stage for future work including: an economic analysis, a larger multi-site study, longer intervention duration, study of extended release buprenorphine, and study of step-down to less intensive interventions.